Medical system and method of use

ABSTRACT

Methods, systems and devices for applying energy to tissue, and more particularly relates to a system for ablating or modifying structures in a body with systems and methods that generate a flow of vapor at a controlled flow rate for applying energy to the body structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/452,515 filed Oct. 27, 2021, now U.S. Pat. No. 11,413,086, which is acontinuation of U.S. patent application Ser. No. 16/684,420 filed Nov.14, 2019, now U.S. Pat. No. 11,457,969, which is a continuation of U.S.patent application Ser. No. 15/912,332 filed Mar. 5, 2018, now U.S. Pat.No. 10,499,973, which is a continuation of U.S. patent application Ser.No. 13/842,632 filed Mar. 15, 2013, now U.S. Pat. No. 9,943,353, thecontents of each of which are incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

This invention relates to medical instruments and systems for applyingenergy to tissue, and more particularly relates to a system for ablatingor modifying structures in a body with systems and methods that generatea flow of vapor at a controlled flow rate for applying energy to thebody structure.

BACKGROUND OF THE INVENTION

Various types of medical instruments utilizing radiofrequency (RF)energy, laser energy, microwave energy and the like have been developedfor delivering thermal energy to tissue, for example to ablate tissue.While such prior art forms of energy delivery work well for someapplications, RF, laser and microwave energy typically cannot causehighly “controlled” and “localized” thermal effects that are desirablein controlled ablation of soft tissue for ablating a controlled depth orfor the creation of precise lesions in such tissue. In general, thenon-linear or non-uniform characteristics of tissue affectelectromagnetic energy distributions in tissue.

What is needed are systems and methods that controllably apply thermalenergy to tissue or body structure from a controlled flow of a vapormedia without the lack of control often associated when RF, laser andmicrowave energy is applied directly to tissue.

This application is related to the following U.S. Non-provisional andProvisional applications: Application No. 61/126,647 filed on May 6,2008 titled MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/126,651filed on May 6, 2008 titled MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/126,612 filed on May 6, 2008 titled MEDICAL SYSTEMAND METHOD OF USE; Application No. 61/126,636 filed on May 6, 2008titled MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/130,345filed on May 31, 2008 titled MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/191,459 filed on Sep. 9, 2008 titled MEDICAL SYSTEMAND METHOD OF USE; Application No. 61/066,396 filed on Feb. 20, 2008titled TISSUE ABLATION SYSTEM AND METHOD OF USE; Application No.61/123,416 filed on Apr. 8, 2008 titled MEDICAL SYSTEM AND METHOD OFUSE; Application No. 61/068,049 filed on Mar. 4, 2008 titled MEDICALSYSTEM AND METHOD OF USE; Application No. 61/123,384 filed on Apr. 8,2008 titled MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/068,130filed on Mar. 4, 2008 titled MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/123,417 filed on Apr. 8, 2008 titled MEDICAL SYSTEMAND METHOD OF USE; Application No. 61/123,412 filed on Apr. 8, 2008titled MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/126,830filed on May 7, 2008 titled MEDICAL SYSTEM AND METHOD OF USE; andApplication No. 61/126,620 filed on May 6, 2008 titled MEDICAL SYSTEMAND METHOD OF USE.

The systems and methods described herein are also related to U.S. patentapplication Ser. No. 10/681,625 filed Oct. 7, 2003 titled “MedicalInstruments and Techniques for Thermally-Mediated Therapies”; Ser. No.11/158,930 filed Jun. 22, 2005 titled “Medical Instruments andTechniques for Treating Pulmonary Disorders”; Ser. No. 11/244,329 filedOct. 5, 2005 titled “Medical Instruments and Methods of Use” and Ser.No. 11/329,381 filed Jan. 10, 2006 titled “Medical Instrument and Methodof Use”; and Ser. No. 13/292,800 entitled “Medical Systems and Methodsof Use” filed Nov. 9, 2011.

All of the above applications are incorporated herein by this referenceand made a part of this specification, together with the specificationsof all other commonly-invented applications cited in the aboveapplications.

SUMMARY OF THE INVENTION

The present devices and methods are adapted to provide an improved meansof controlled thermal energy delivery to localized tissue volumes, forexample for ablating, sealing, coagulating or otherwise damagingtargeted tissue.

In general, the thermally-mediated treatment method comprises causing avapor-to-liquid phase state change in a selected media at a targetedtissue site thereby applying thermal energy substantially equal to theheat of vaporization of the selected media to the tissue site. Thethermally-mediated therapy can be delivered to tissue by suchvapor-to-liquid phase transitions, or “internal energy” releases, aboutthe working surfaces of several types of instruments for ablativetreatments of soft tissue. FIGS. 1A and 1B illustrate the phenomena ofphase transitional releases of internal energies. Such internal energyinvolves energy on the molecular and atomic scale—and in polyatomicgases is directly related to intermolecular attractive forces, as wellas rotational and vibrational kinetic energy. In other words, the methodand devices described herein exploit the phenomenon of internal energytransitions between gaseous and liquid phases that involve very largeamounts of energy compared to specific heat.

It has been found that the controlled application of such energy in acontrolled media-tissue interaction solves many of the vexing problemsassociated with energy-tissue interactions in RF, laser and ultrasoundmodalities. The apparatus described herein can provide a vaporizationchamber in the interior of an instrument, in an instrument working endor in a source remote from the instrument end. A source provides liquidmedia to the interior vaporization chamber wherein energy is applied tocreate a selected volume of vapor media. In the process of theliquid-to-vapor phase transition of a liquid media, for example water,large amounts of energy are added to overcome the cohesive forcesbetween molecules in the liquid, and an additional amount of energy isrequired to expand the liquid 1000+ percent (PΔD) into a resulting vaporphase (see FIG. 1A). Conversely, in the vapor-to-liquid transition, suchenergy will be released at the phase transition at the interface withthe targeted tissue site. That is, the heat of vaporization is releasedat the interface when the media transitions from gaseous phase to liquidphase wherein the random, disordered motion of molecules in the vaporregain cohesion to convert to a liquid media. This release of energy(defined as the capacity for doing work) relating to intermolecularattractive forces is transformed into therapeutic heat for athermotherapy at the interface with the targeted body structure. Heatflow and work are both ways of transferring energy.

In FIG. 1A, the simplified visualization of internal energy is usefulfor understanding phase transition phenomena that involve internalenergy transitions between liquid and vapor phases. If heat were addedat a constant rate in FIG. 1A (graphically represented as 5 calories/gmblocks) to elevate the temperature of water through its phase change toa vapor phase, the additional energy required to achieve the phasechange (latent heat of vaporization) is represented by the large numberof 110+ blocks of energy at 100° C. in FIG. 1A. Still referring to FIG.1A, it can be easily understood that all other prior art ablationmodalities—RF, laser, microwave and ultrasound—create energy densitiesby simply ramping up calories/gm as indicated by the temperature rangefrom 37° C. through 100° C. as in FIG. 1A. The prior art modalities makeno use of the phenomenon of phase transition energies as depicted inFIG. 1A.

FIG. 1B graphically represents a block diagram relating to energydelivery aspects of the present devices and methods. The system canprovide for insulative containment of an initial primary energy-mediainteraction within an interior vaporization chamber of a medicalthermotherapy system. The initial, ascendant energy-media interactiondelivers energy sufficient to achieve the heat of vaporization of aselected liquid media, such as water or saline solution, within aninterior of the system. This aspect of the technology requires a highlycontrolled energy source wherein a computer controller may need tomodulate energy application between very large energy densities toinitially surpass the latent heat of vaporization with some energysources (e.g. a resistive heat source, an RF energy source, a lightenergy source, a microwave energy source, an ultrasound source and/or aninductive heat source) and potential subsequent lesser energy densitiesfor maintaining a high vapor quality. Additionally, a controller mustcontrol the pressure of liquid flows for replenishing the selectedliquid media at the required rate and optionally for controllingpropagation velocity of the vapor phase media from the working endsurface of the instrument. In use, the methods described herein cancomprise the controlled application of energy to achieve the heat ofvaporization as in FIG. 1A and the controlled vapor-to-liquid phasetransition and vapor exit pressure to thereby control the interaction ofa selected volume of vapor at the interface with tissue. Thevapor-to-liquid phase transition can deposit 400, 500, 600 or morecal/gram within the targeted tissue site to perform the thermal ablationwith the vapor in typical pressures and temperatures.

The following disclosure includes methods for a controlled treatment ofa body structure. Such methods can include a flow-based system havingflow control as disclosed. These systems allow controlled application ofthe amount of energy delivered or allow for knowing the rate of energydelivered. The present methods and devices address the building oftissue back-pressure that might impede vapor flow thus making actualenergy delivery uncertain.

In one variation, the method includes positioning a working end of avapor delivery system at a targeted site in a body; providing a flow ofliquid media at a selected fluid flow rate in the system and convertingthe liquid media to vapor media where a vapor flow rate corresponds tothe selected fluid flow rate; and delivering the vapor media to thetargeted site for a selected time interval thereby providing acontrolled amount of energy to the targeted site.

The methods can include actuating an RF source configured to inductivelyheat a structure having a flow channel that carries the flow of liquidmedia.

In various alternatives, the selected fluid flow rate is maintained at aconstant rate over the selected time interval. Also the method canutilize a flow controller and selecting the fluid flow rate on acontroller interface.

The method can include selecting an energy application rate on acontroller interface, selecting the time interval on a controllerinterface and/or selecting the total calories applied to tissue on acontroller interface. The controller can be programmable to maintain thefluid flow rate at a constant over the selected time interval.

The flow controller can be programmable to maintain the fluid flow rateat first parameters over a first time interval and maintain the fluidflow rate at second parameters over a second time interval.Alternatively, or in combination, the flow controller is programmable tomodulate the fluid flow rate over at least one selected time interval.

In another variation, a medical method for treating body structure caninclude providing a vapor delivery system including a flow channel andenergy applicator for applying energy to a flow of liquid media in theflow channel; introducing a first flow of liquid media at a first liquidflow rate into the flow channel and converting the liquid media to vapormedia, wherein a first vapor flow rate is configured for at least one ofpre-heating and maintaining heat in the flow channel; and introducing asecond flow of liquid media at a second liquid flow rate into the flowchannel and converting the liquid media to vapor media, wherein secondvapor flow rate is configured for exiting at least one vapor outlet forapplying energy to the body structure.

A variation of the above method includes, after introducing a first flowof liquid media, positioning a working end of the system into orproximate the body structure, wherein the first vapor flow rate isconfigured to prevent at least one of gas and body fluids from migratinginto the least one vapor outlet.

The present disclosure also includes medical systems for applying energyto body structure. One such system includes a handle with an elongatedmember coupled to the handle; an electrical source operatively coupledto a coil within the handle; an inductively heatable structure proximatepositioned proximate to the coil; a pump and liquid media source incommunication with a flow channel in the structure, the flow channelhaving an least one outlet in a distal end of the elongated member; acontroller operatively coupled to the electrical source and pump; atleast one of a flow sensor, pressure sensor and temperature sensor forsending signals of operating parameters to the controller; and whereinthe controller is configured to operate the electrical source and pumpat selected parameters to inductively heat the structure to therebyconvert a flow of the liquid media to a flow of vapor media in the flowchannel which exits the at least one outlet to apply energy to bodystructure.

The controller can include a user interface configured withuser-selectable pre-selects for at least one of (i) liquid media flowrate, (ii) liquid media flow interval, (iii) modulation of the liquidmedia flow rate within a time interval, (iv) energy application ratecorresponding to energy released in a phase change of vapor to liquid,(v) pulsed flows of the liquid media and (vi) total applied energy.Alternatively, or in combination, the controller includes an algorithmto modulate electrical energy applied to the coil to maintain thetemperature of the inductively heatable structure within a selectedrange. In another variation, the controller includes an algorithm tomodulate the liquid media flow rate to maintain the temperature of theinductively heatable structure within a selected range.

In yet another variation, the controller includes an algorithm andlook-up table configured for selection of operating parameters of theelectrical source corresponding to each user-selected liquid media flowrate.

Controllers described herein can also include a disable mechanismconfigured to disable electrical energy delivery to the coil based onfeedback from at least one of the flow sensor, pressure sensor andtemperature sensor or a disable mechanism configured to disable the pumpand liquid media flow based on feedback from at least one of the flowsensor, pressure sensor and temperature sensor.

Another method for delivering energy to body tissue can includeintroducing a working end of a vapor delivery probe into a targeted sitein tissue; providing a flow of a condensable vapor under firstoperational parameters from the working end to modify the targeted siteto permit enhanced extracellular vapor propagation therein; andproviding a flow of the condensable vapor under second different flowparameters from the working end to cause cell death in the targetedsite.

In one variation, a first operational parameters include a firstpressure that is higher than a second pressure in the second flowparameters. The first operational parameters can also include a firstflow rate that is higher than a second flow rate of the second flowparameters. The first operational parameters can include a pulsed flowor a non-pulsed flow.

Another method for delivering energy to body tissue includes introducinga working end of a vapor delivery probe into a targeted site in tissue;providing a first flow of a condensable vapor from the probe for a firstinterval to cause convective heating within the targeted site; andproviding a different second flow of condensable vapor for a secondinterval to cause cell death in the targeted site.

The present disclosure also includes one or more apparatus for applyingenergy to body structure. Such devices can include a vapor deliverysystem with a flow channel extending to at least one outlet in a workingend; a liquid media source and pump system configured to provide a flowof the liquid media into the flow channel; a heat source for convertingthe flow of the liquid media into a flow of vapor media in the flowchannel; and a controller adapted to control operating parameters of theliquid media source and heat source; wherein the controller includes auser interface configured with user-selectable pre-selects for at leastone of (i) liquid media flow rate, (ii) liquid media flow interval,(iii) modulation of the liquid media flow rate within a time interval,(iv) energy application rate corresponding to energy released in a phasechange of vapor to liquid, (v) pulsed flows of the liquid media and (vi)total applied energy corresponding to energy released in a phase changeof vapor to liquid.

Variations of the device can comprise an electrical source configured toinductively heat a wall of a flow channel to thereby vaporize the flowof the liquid media therein.

As noted above, the controller can include a look-up table andalgorithms configured for selection of operating parameters of theelectrical source corresponding to each user-selected liquid media flowrate. The controller can also be configured to idle the vapor deliversystem to provide instant-on therapeutic vapor media flows.

In one variation the controller idles the vapor deliver system byproviding non-therapeutic vapor media flows through at least part of theflow channel to maintain heat in the wall of the flow channel. Thecontroller can also idle the system by providing a liquid media flowrate of less rate than 1 cc/min together with corresponding operatingparameters of the electrical source to vaporize the flow of liquidmedia.

The devices described herein can further include at least onetemperature sensor in a wall of the flow channel configured to sendsignals to the controller.

Controllers used for the device can include algorithms for modulatingthe liquid media flow rate or the operating parameters of the heatsource in response to temperature signals. The controller can alsoinclude algorithms for modulating the liquid media flow rate or theoperating parameters of the heat source in response to pressure signals.

The devices described herein can include at least one pressure sensor incommunication with the flow channel configured to send signals to thecontroller.

Another method includes a method of treating a blood pressure disorderin a human patient comprising navigating the working end of a vapordelivery catheter intravascularly to a position proximate a baroreceptorin a vessel wall and delivering a condensable vapor from the working tomodify function of the baroreceptor.

Such treatments can occur in a carotid artery or any other vessel.

Another variation of a method includes a medical method for treatingbody structure, comprising: positioning a working end of a vapordelivery probe at or proximate to a targeted site in a body; andutilizing a pump system to provide a flow of liquid media at apredetermined fluid flow rate into the probe and converting the liquidmedia to vapor media thereby providing a corresponding vapor flow rateto the site, wherein the pump system is configured to deliver the liquidand vapor media at a substantially constant rate not affected byresistance to the flow of vapor media to the site.

Such method can include treatment of targeted sites, including but notlimited to benign or malignant tumorous tissue; uterine fibroids; lungtissue; lung tumors or nodules; an esophagus or its inner lining; a wallof a renal artery or wall of a carotid artery; nerve tissue, abaroreceptor; a carotid body, skin, adipose tissue, bone, disc, discnucleus, ligaments, cartilage, synovial tissue, myelomas, cervicaltissue, endometrium, digestive tract tissue, stomach walls, intestinalwalls, hemorrhoids, soft palate, tongue tissue, an ulcer, wart, lymphnode, breast duct, sinus tissue, arterial and venous malformations,vasculature, brain tissue, nerve roots in a tooth, heart tissue and eyetissue.

Additional advantages of the method and devices are apparent from thefollowing description, the accompanying drawings and the appendedclaims.

All patents, patent applications and publications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication or patent application was specificallyand individually indicated to be incorporated by reference.

In addition, it is intended that combinations of aspects of the systemsand methods described herein as well as the various embodimentsthemselves, where possible, are within the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a graphical depiction of the quantity of energy needed toachieve the heat of vaporization of water.

FIG. 1B is a diagram of phase change energy release that underlies asystem and method of the devices and methods.

FIG. 2 provides a schematic view of a variation of a medical systemadapted for treating a tissue target, wherein the treatment comprises anablation or thermotherapy and the tissue target can comprise anymammalian soft tissue to be ablated, sealed, contracted,

FIG. 3 is a block diagram of an exemplary control method.

FIG. 4A is an illustration of the working end of FIG. 2 being introducedinto soft tissue to treat a targeted tissue volume.

FIG. 4B is an illustration of the working end of FIG. 4A showing thepropagation of vapor media in tissue in a method of use in ablating atumor.

FIG. 5 is an illustration of a working end similar to FIGS. 4A-4B withvapor outlets comprising microporosities in a porous wall.

FIG. 6A is a schematic view of a needle-type working end of a vapordelivery tool for applying energy to tissue.

FIG. 6B is a schematic view of an alternative needle-type working endsimilar to FIG. 6A.

FIG. 6C is a schematic view of a retractable needle-type working endsimilar to FIG. 6B.

FIG. 6D is a schematic view of a working end with multiple shape-memoryneedles.

FIG. 6E is a schematic view of a working end with deflectable needles.

FIG. 6F is a schematic view of a working end with a rotating element fordirecting vapor flows.

FIG. 6G is another view of the working end of FIG. 6F.

FIG. 6H is a schematic view of a working end with a balloon.

FIG. 6I is a schematic view of an articulating working end.

FIG. 6J is a schematic view of an alternative working end with RFelectrodes.

FIG. 6K is a schematic view of an alternative working end with aresistive heating element.

FIG. 6L is a schematic view of a working end with a tissue-capturingloop.

FIG. 6M is a schematic view of an alternative working end with jaws forcapturing and delivering vapor to tissue.

FIG. 7 is a schematic view of an alternative working end with jaws forcapturing and delivering vapor to tissue.

FIG. 8 is a schematic view of an alternative working end with jaws forcapturing and delivering vapor to tissue.

FIG. 9 is a partly disassembled view of a variation of a handle andvariation of an inductive vapor generator system for use with devicesand methods described herein.

FIG. 10 is an enlarged schematic view of another variation of aninductive vapor generator of FIG. 9 .

FIG. 11A is an illustration of a variation of a method where a workingend of a catheter is introduced into the lumen of a renal artery fortreatment of electrical signal transmission characteristics in nervefibers in the artery.

FIG. 11B illustrates an enlarged schematic view of the catheter workingend of FIG. 11A.

FIG. 11C illustrates the expansion of a balloon carried by the workingend of FIG. 11B and the high pressure jetting of a flowable media from ajetting outlet into the arterial wall to cause damage to electricalsignal carrying structures in the vessel wall.

FIG. 11D illustrates a subsequent step of deflating the balloonfollowing the termination of flow media delivery to thereby provide atreated region.

FIG. 12A is a magnified view of a portion of a catheter working end thatshows a projecting feature that surrounds the jetting outlet.

FIG. 12B is a magnified view of another projecting feature with a sharpapex that surrounds the jetting outlet in a catheter working end.

FIG. 12C is a magnified view of another projecting feature thatsurrounds a plurality of jetting outlets in a catheter working end.

FIG. 12D is a magnified view of another projecting feature thatsurrounds jetting outlets that have converging axes.

FIG. 12E is a magnified view of another working end wherein amicro-needle is extendable to penetrate a jetting outlet into the vesselwall.

FIG. 13A is a schematic view of a blood vessel following treatment withthe method of FIGS. 11A-11D wherein the jetted media flows damage nervefibers in targeted partly-annular treatment zones.

FIG. 13B is another schematic view of a blood vessel following treatmentwherein the jetted media flows damage nerve fibers in targeted spiralingtreatment zone.

FIG. 13C is another schematic view of a blood vessel post-treatmentwherein the jetted media flows damage nerve fibers in targeted spacedapart zones.

FIG. 14A illustrates another catheter working end and method of usewherein the working end has a spiral configuration following expansionby an expansion member.

FIG. 14B illustrates the catheter working end of FIG. 14A in an expandedconfiguration to thereby treat tissue in a spiral pattern.

FIG. 15A is a schematic illustration and block diagram relating to thecatheter system of FIGS. 14A-14B wherein the catheter system has flowmedia inflow and outflow lumens for a circulating flow together with avalve system for creating high pressure flow media jetting from aplurality of jetting outlets.

FIG. 15B is an illustration and block diagram similar to that of FIG.15A wherein the valve system is actuated to cause high pressure flowmedia to jet outwardly from the plurality of jetting outlets.

FIG. 16 is an illustration and block diagram of another catheter workingend with first and second catheter sleeve portions that can be expandedapart by a balloon; the working end configured with a plurality of flowmedia jetting outlets.

FIG. 17 is an illustration and block diagram of another catheter workingend that can be articulated into an expanded cross section with a pullwire to engage the vessel wall; the working end configured with aplurality of flow media jetting outlets.

FIG. 18 is an illustration and block diagram of another catheter workingend that include first and second flow media source and first and secondinflow pathway for providing contemporaneous or sequential jetting ofliquid cutting jets and vapor jets from separate outlets.

FIG. 19 is a view of another embodiment of a vapor delivery system thatincludes a hand-held probe with an inductive heating form of vaporgenerator carried in a probe handle together with a disposable,de-matable vapor delivery needle.

FIG. 20 is an enlarged view of the working end of the vapor deliveryneedle of FIG. 19 .

FIG. 21 is an exploded view of the components of the vapor deliverysystem of FIG. 19 .

FIG. 22 is a cross-section of the vapor delivery needle shaft of FIG. 19.

FIG. 23 is another embodiment of a vapor delivery system similar to thatof FIG. 19 wherein the disposable assembly includes a vapor deliveryneedle portion together with an inductively heatable portion.

FIG. 24 is another variation of a vapor delivery system and method forusing vapor delivery to treat a blood pressure disorder by modifying thefunction of a baroreceptor in an arterial wall.

FIG. 25 is another variation of a vapor delivery system and method forusing vapor to treat cervical neoplasia.

DETAILED DESCRIPTION OF THE INVENTION

As used in the specification, “a” or “an” means one or more. As used inthe claim(s), when used in conjunction with the word “comprising”, thewords “a” or “an” mean one or more. As used herein, “another” means asleast a second or more. “Substantially” or “substantial” mean largelybut not entirely. For example, substantially may mean about 10% to about99.999, about 25% to about 99.999% or about 50% to about 99.999%.

Treatment Liquid Source, Energy Source, Controller

Referring to FIG. 2 , a schematic view of a variation of a medicalsystem 100 is shown where the system 100 is adapted for treating atissue target, wherein the treatment comprises an ablation orthermotherapy and the tissue target can comprise any mammalian softtissue to be ablated, sealed, contracted, coagulated, damaged or treatedto elicit an immune response. The system 100 can include an instrumentor probe body 102 with a proximal handle end 104 and an extensionportion 105 having a distal or working end indicated at 110. In oneembodiment depicted in FIG. 2 , the handle end 104 and extension portion105 generally extend about longitudinal axis 115. In the embodiment ofFIG. 2 , the extension portion 105 is a substantially rigid tubularmember with at least one flow channel therein, but additional variationscan encompass extension portions 105 of any mean diameter and any axiallength, rigid or flexible, suited for treating a particular tissuetarget. In one embodiment, a rigid extension portion 105 can comprise a20 Ga. to 40 Ga. needle with a short length for thermal treatment of apatient's cornea or a somewhat longer length for treating a patient'sretina. In another embodiment, an elongate extension portion 105 of avapor delivery tool can comprise a single needle or a plurality ofneedles having suitable lengths for tumor or soft tissue ablation in aliver, breast, gall bladder, prostate, bone and the like. In anotherembodiment, an elongate extension portion 105 can comprise a flexiblecatheter for introduction through a body lumen to access a tissuetarget, with a diameter ranging from about 1 to 10 mm. In anotherembodiment, the extension portion 105 or working end 110 can bearticulatable, deflectable or deformable. The probe handle end 104 canbe configured as a hand-held member, or can be configured for couplingto a robotic surgical system. In another embodiment, the working end 110carries an openable and closeable structure for capturing tissue betweenfirst and second tissue-engaging surfaces, which can comprise actuatablecomponents such as one or more clamps, jaws, loops, snares and the like.The proximal handle end 104 of the probe can carry various actuatormechanisms known in the art for actuating components of the system 100,and/or one or more footswitches can be used for actuating components ofthe system.

As can be seen in FIG. 2 , the system 100 further includes a source 120of a flowable liquid treatment media 121 that communicates with a flowchannel 124 extending through the probe body 102 to at least one outlet125 in the working end 110. The outlet 125 can be singular or multipleand have any suitable dimension and orientation as will be describedfurther below. The distal tip 130 of the probe can be sharp forpenetrating tissue, or can be blunt-tipped or open-ended with outlet125. Alternatively, the working end 110 can be configured in any of thevarious embodiments shown in FIGS. 6A-6M and described further below.

In one embodiment shown in FIG. 2 , an RF energy source 140 isoperatively connected to a thermal energy source or emitter (e.g.,opposing polarity electrodes 144 a, 144 b) in interior chamber 145 inthe proximal handle end 104 of the probe for converting the liquidtreatment media 121 from a liquid phase media to a non-liquid vaporphase media 122 with a heat of vaporization in the range of 60° C. to200° C., or 80° C. to 120° C. A vaporization system using RF energy andopposing polarity electrodes is disclosed in co-pending U.S. patentapplication Ser. No. 11/329,381 which is incorporated herein byreference. Another embodiment of a vapor generation system is describedbelow in the Section titled “INDUCTIVE VAPOR GENERATION SYSTEMS”. In anysystem embodiment, for example in the system of FIG. 2 , a controller150 is provided that comprises a computer control system configured forcontrolling the operating parameters of inflows of liquid treatmentmedia source 120 and energy applied to the liquid media by an energysource to cause the liquid-to-vapor conversion. The vapor generationsystems described herein can consistently produce a high quality vaporhaving a temperature of at least 80° C., 100° C. 120° C., 140° C. and160° C.

As can be seen in FIG. 2 , the medical system 100 can further include anegative pressure or aspiration source indicated at 155 that is in fluidcommunication with a flow channel in probe 102 and working end 110 foraspirating treatment vapor media 122, body fluids, ablation by-products,tissue debris and the like from a targeted treatment site, as will befurther described below. In FIG. 2 , the controller 150 also is capableof modulating the operating parameters of the negative pressure source155 to extract vapor media 122 from the treatment site or from theinterior of the working end 110 by means of a recirculation channel tocontrol flows of vapor media 122 as will be described further below.

In another embodiment, still referring to FIG. 2 , medical system 100further includes secondary media source 160 for providing an inflow of asecond media, for example a biocompatible gas such as CO₂. In onemethod, a second media that includes at least one of depressurized CO₂,N₂, O₂ or H₂O can be introduced and combined with the vapor media 122.This second media 162 is introduced into the flow of non-ionized vapormedia for lowering the mass average temperature of the combined flow fortreating tissue. In another embodiment, the medical system 100 includesa source 170 of a therapeutic or pharmacological agent or a sealantcomposition indicated at 172 for providing an additional treatmenteffect in the target tissue. In FIG. 2 , the controller indicated at 150also is configured to modulate the operating parameters of source 160and 170 to control inflows of a secondary vapor 162 and therapeuticagents, sealants or other compositions indicated at 172.

In FIG. 2 , it is further illustrated that a sensor system 175 iscarried within the probe 102 for monitoring a parameter of the vapormedia 122 to thereby provide a feedback signal FS to the controller 150by means of feedback circuitry to thereby allow the controller tomodulate the output or operating parameters of treatment media source120, energy source 140, negative pressure source 155, secondary mediasource 160 and therapeutic agent source 170. The sensor system 175 isfurther described below, and in one embodiment comprises a flow sensorto determine flows or the lack of a vapor flow. In another embodiment,the sensor system 175 includes a temperature sensor. In anotherembodiment, sensor system 175 includes a pressure sensor. In anotherembodiment, the sensor system 175 includes a sensor arrangement fordetermining the quality of the vapor media, e.g., in terms of vaporsaturation or the like. The sensor systems will be described in moredetail below.

Now turning to FIGS. 2 and 3 , the controller 150 is capable of alloperational parameters of system 100, including modulating theoperational parameters in response to preset values or in response tofeedback signals FS from sensor system(s) 175 within the system 100 andprobe working end 110. In one embodiment, as depicted in the blockdiagram of FIG. 3 , the system 100 and controller 150 are capable ofproviding or modulating an operational parameter comprising a flow rateof liquid phase treatment media 122 from pressurized source 120, whereinthe flow rate is within a range from about 0.001 to 20 ml/min, 0.010 to10 ml/min or 0.050 to 5 ml/min. The system 100 and controller 150 arefurther capable of providing or modulating another operational parametercomprising the inflow pressure of liquid phase treatment media 121 in arange from 0.5 to 1000 psi, 5 to 500 psi, or 25 to 200 psi. The system100 and controller 150 are further capable of providing or modulatinganother operational parameter comprising a selected level of energycapable of converting the liquid phase media into a non-liquid,non-ionized gas phase media, wherein the energy level is within a rangeof about 5 to 2,500 watts; 10 to 1,000 watts or 25 to 500 watts. Thesystem 100 and controller 150 are capable of applying the selected levelof energy to provide the phase conversion in the treatment media over aninterval ranging from 0.1 seconds to 10 minutes; 0.5 seconds to 5minutes, and 1 second to 60 seconds. The system 100 and controller 150are further capable of controlling parameters of the vapor phase mediaincluding the flow rate of non-ionized vapor media proximate an outlet125, the pressure of vapor media 122 at the outlet, the temperature ormass average temperature of the vapor media, and the quality of vapormedia as will be described further below.

FIGS. 4A and 4B illustrate a working end 110 of the system 100 of FIG. 2and a method of use. As can be seen in FIG. 4A, a working end 110 issingular and configured as a needle-like device for penetrating intoand/or through a targeted tissue T such as a tumor in a tissue volume176. The tumor can be benign, malignant, hyperplastic or hypertrophictissue, for example, in a patient's breast, uterus, lung, liver, kidney,gall bladder, stomach, pancreas, colon, GI tract, bladder, prostate,bone, vertebra, eye, brain or other tissue. In one variation, theextension portion 104 is made of a metal, for example, stainless steel.Alternatively or additionally, at least some portions of the extensionportion can be fabricated of a polymer material such as PEEK, PTFE,Nylon or polypropylene. Also optionally, one or more components of theextension portion are formed of coated metal, for example, a coatingwith Teflon® to reduce friction upon insertion and to prevent tissuesticking following use. In one embodiment as shown in FIG. 4A, theworking end 110 includes a plurality of outlets 125 that allow vapormedia to be ejected in all radial directions over a selected treatmentlength of the working end. In another embodiment, the plurality ofoutlets can be symmetric or asymmetric axially or angularly about theworking end 110.

In one embodiment, the outer diameter of extension portion 105 orworking end 110 is, for example, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 5 mm or anintermediate, smaller or larger diameter. Optionally, the outlets cancomprise microporosities 177 in a porous material as illustrated in FIG.5 for diffusion and distribution of vapor media flows about the surfaceof the working end. In one such embodiment, such porosities provide agreater restriction to vapor media outflows than adjacent targetedtissue, which can vary greatly in vapor permeability. In this case, suchmicroporosities ensure that vapor media outflows will occursubstantially uniformly over the surface of the working end. Optionally,the wall thickness of the working end 110 is from 0.05 to 0.5 mm.Optionally, the wall thickness decreases or increases towards the distalsharp tip 130 (FIG. 5 ). In one embodiment, the dimensions andorientations of outlets 125 are selected to diffuse and/or direct vapormedia propagation into targeted tissue T and more particularly to directvapor media into all targeted tissue to cause extracellular vaporpropagation and thus convective heating of the target tissue asindicated in FIG. 4B. As shown in FIGS. 4A-4B, the shape of the outlets125 can vary, for example, round, ellipsoid, rectangular, radiallyand/or axially symmetric or asymmetric. As shown in FIG. 5 , a sleeve178 can be advanced or retracted relative to the outlets 125 to providea selected exposure of such outlets to provide vapor injection over aselected length of the working end 110. Optionally, the outlets can beoriented in various ways, for example so that vapor media 122 is ejectedperpendicular to a surface of working end 110, or ejected is at an anglerelative to the axis 115 or angled relative to a plane perpendicular tothe axis. Optionally, the outlets can be disposed on a selected side orwithin a selected axial portion of working end, wherein rotation oraxial movement of the working end will direct vapor propagation andenergy delivery in a selected direction. In another embodiment, theworking end 110 can be disposed in a secondary outer sleeve that hasapertures in a particular side thereof for angular/axial movement intargeted tissue for directing vapor flows into the tissue.

FIG. 4B illustrates the working end 110 of system 100 ejecting vapormedia from the working end under selected operating parameters, forexample a selected pressure, vapor temperature, vapor quantity, vaporquality and duration of flow. The duration of flow can be a selectedpre-set or the hyperechoic aspect of the vapor flow can be imaged bymeans of ultrasound to allow the termination of vapor flows byobservation of the vapor plume relative to targeted tissue T. Asdepicted schematically in FIG. 4B, the vapor can propagateextracellularly in soft tissue to provide intense convective heating asthe vapor collapses into water droplets which result in effective tissueablation and cell death. As further depicted in FIG. 4B, the tissue istreated to provide an effective treatment margin 179 around a targetedtumorous volume. The vapor delivery step is continuous or can berepeated at a high repetition rate to cause a pulsed form of convectiveheating and thermal energy delivery to the targeted tissue. Therepetition rate vapor flows can vary, for example with flow durationsintervals from 0.01 to 20 seconds and intermediate off intervals from0.01 to 5 seconds or intermediate, larger or smaller intervals.

In an exemplary embodiment as shown in FIGS. 4A-4B, the extensionportion 105 can be a unitary member such as a needle. In anotherembodiment, the extension portion 105 or working end 110 can be adetachable flexible body or rigid body, for example of any type selectedby a user with outlet sizes and orientations for a particular procedurewith the working end attached by threads or Luer fitting to a moreproximal portion of probe 102.

In other embodiments, the working end 110 can comprise needles withterminal outlets or side outlets as shown in FIGS. 6A-6B. The needle ofFIGS. 6A and 6B can comprise a retractable needle as shown in FIG. 6Ccapable of retraction into probe or sheath 180 for navigation of theprobe through a body passageway or for blocking a portion of the vaporoutlets 125 to control the geometry of the vapor-tissue interface. Inanother embodiment shown in FIG. 6D, the working end 110 can havemultiple retractable needles that are of a shape memory material. Inanother embodiment as depicted in FIG. 6E, the working end 110 can haveat least one deflectable and retractable needle that deflects relativeto an axis of the probe 180 when advanced from the probe. In anotherembodiment, the working end 110 as shown in FIGS. 6F-6G can comprise adual sleeve assembly wherein vapor-carrying inner sleeve 181 rotateswithin outer sleeve 182 and wherein outlets in the inner sleeve 181 onlyregister with outlets 125 in outer sleeve 182 at selected angles ofrelative rotation to allow vapor to exit the outlets. This assembly thusprovides for a method of pulsed vapor application from outlets in theworking end. The rotation can be from about 1 rpm to 1000 rpm.

In another embodiment of FIG. 6H, the working end 110 has a heatapplicator surface with at least one vapor outlet 125 and at least oneexpandable member 183 such as a balloon for positioning the heatapplicator surface against targeted tissue. In another embodiment asshown in FIG. 6I, the working end can be a flexible material that isdeflectable, for example, by a pull-wire. The embodiments of FIGS. 6Hand 6I have configurations for use in treating various other medicalindications, such as atrial fibrillation, for example in pulmonary veinablation.

In another embodiment of FIG. 6J, the working end 110 includesadditional optional heat applicator means which can comprise amono-polar electrode cooperating with a ground pad or bi-polarelectrodes 184 a and 184 b for applying energy to tissue. In FIG. 6K,the working end 110 includes resistive heating element 187 for applyingenergy to tissue. FIG. 6L depicts a snare for capturing tissue to betreated with vapor and FIG. 6M illustrates a clamp or jaw structure. Theworking end 110 of FIG. 6M includes means actuatable from the handle foroperating the jaws.

Sensors for Vapor Flows, Temperature, Pressure, Quality

Referring to FIG. 7 , one embodiment of sensor system 175 is shown thatis carried by working end 110 of the probe 102 depicted in FIG. 2 fordetermining a first vapor media flow parameter, which can consist ofdetermining whether the vapor flow is in an “on” or “off” operatingmode. The working end 110 of FIG. 7 comprises a sharp-tipped needlesuited for needle ablation of any neoplasia or tumor tissue, such as abenign or malignant tumor as described previously, but can also be anyother form of vapor delivery tool. The needle can be any suitable gaugeand in one embodiment has a plurality of vapor outlets 125. In a typicaltreatment of targeted tissue, it is important to provide a sensor andfeedback signal indicating whether there is a flow, or leakage, of vapormedia 122 following treatment or in advance of treatment when the systemis in “off” mode. Similarly, it is important to provide a feedbacksignal indicating a flow of vapor media 122 when the system is in “on”mode. In the embodiment of FIG. 7 , the sensor comprises at least onethermocouple or other temperature sensor indicated at 185 a, 185 b and185 c that are coupled to leads (indicated schematically at 186 a, 186 band 186 c) for sending feedback signals to controller 150. Thetemperature sensor can be a singular component or can be plurality ofcomponents spaced apart over any selected portion of the probe andworking end. In one embodiment, a feedback signal of any selectedtemperature from any thermocouple in the range of the heat ofvaporization of treatment media 122 would indicate that flow of vapormedia, or the lack of such a signal would indicate the lack of a flow ofvapor media. The sensors can be spaced apart by at least 0.05 mm, 1 mm,5 mm, 10 mm and 50 mm. In other embodiments, multiple temperaturesensing events can be averaged over time, averaged between spaced apartsensors, the rate of change of temperatures can be measured and thelike. In one embodiment, the leads 186 a, 186 b and 186 c are carried inan insulative layer of wall 188 of the extension member 105. Theinsulative layer of wall 188 can include any suitable polymer or ceramicfor providing thermal insulation. In one embodiment, the exterior of theworking end also is also provided with a lubricious material such asTeflon® which further insures against any tissue sticking to the workingend 110.

Still referring to FIG. 7 , a sensor system 175 can provide a differenttype of feedback signal FS to indicate a flow rate or vapor media basedon a plurality of temperature sensors spaced apart within flow channel124. In one embodiment, the controller 150 includes algorithms capableof receiving feedback signals FS from at least first and secondthermocouples (e.g., 185 a and 185 c) at very high data acquisitionspeeds and compares the difference in temperatures at the spaced apartlocations. The measured temperature difference, when further combinedwith the time interval following the initiation of vapor media flows,can be compared against a library to thereby indicate the flow rate.

Another embodiment of sensor system 175 in a similar working end 110 isdepicted in FIG. 8 , wherein the sensor is configured for indicatingvapor quality—in this case based on a plurality of spaced apartelectrodes 190 a and 190 b coupled to controller 150 and an electricalsource (not shown). In this embodiment, a current flow is providedwithin a circuit to the spaced apart electrodes 190 a and 190 b andduring vapor flows within channel 124 the impedance will vary dependingon the vapor quality or saturation, which can be processed by algorithmsin controller 150 and can be compared to a library of impedance levels,flow rates and the like to thereby determine vapor quality. It isimportant to have a sensor to provide feedback of vapor quality, whichdetermines how much energy is being carried by a vapor flow. The term“vapor quality” is herein used to describe the percentage of the flowthat is actually water vapor as opposed to water droplets that is notphase-changed. In another embodiment (not shown) an optical sensor canbe used to determine vapor quality wherein a light emitter and receivercan determine vapor quality based on transmissibility or reflectance ofa vapor flow.

FIG. 8 further depicts a pressure sensor 192 in the working end 110 forproviding a signal as to vapor pressure. In operation, the controllercan receive the feedback signals FS relating to temperature, pressureand vapor quality to thereby modulate all other operating parametersdescribed above to optimize flow parameters for a particular treatmentof a target tissue, as depicted in FIG. 1 . In one embodiment, a MEMSpressure transducer is used, which is known in the art. In anotherembodiment, a MEMS accelerometer coupled to a slightly translatablecoating can be utilized to generate a signal of changes in flow rate, ora MEMS microphone can be used to compare against a library of acousticvibrations to generate a signal of flow rates.

Inductive Vapor Generation Systems

FIGS. 9 and 10 depict a vapor generation component that utilizes and aninductive heating system within a handle portion 400 of the probe orvapor delivery tool 405. In FIG. 9 , it can be seen that a pressurizedsource of liquid media 120 (e.g., water or saline) is coupled by conduit406 to a quick-connect fitting 408 to deliver liquid into a flow channel410 extending through an inductive heater 420 in probe handle 400 to atleast one outlet 425 in the working end 426. In one embodiment shown inFIG. 9 , the flow channel 410 has a bypass or recirculation channelportion 430 in the handle or working end 426 that can direct vapor flowsto a collection reservoir 432. In operation, a valve 435 in the flowchannel 410 thus can direct vapor generated by inductive heater 420 toeither flow channel portion 410′ or the recirculation channel portion430. In the embodiment of FIG. 10 , the recirculation channel portion430 also is a part of the quick-connect fitting 408.

In FIG. 9 , it can be seen that the system includes a computercontroller 150 that controls (i) the electromagnetic energy source 440coupled to inductive heater 420, (ii) the valve 435 which can be anelectrically-operated solenoid, (iii) an optional valve 445 in therecirculation channel 430 that can operate in unison with valve 435, and(iv) optional negative pressure source 448 operatively coupled to the erecirculation channel 430.

In general, one variation of a system can provide a small handhelddevice including an assembly that utilizes electromagnetic induction toturn a sterile water flow into superheated or dry vapor which can ispropagated from at least one outlet in a vapor delivery tool tointerface with tissue and thus ablate tissue. In one aspect, anelectrically-conducting microchannel structure or other flow-permeablestructure is provided and an inductive coil causes electric currentflows in the structure. Eddies within the current create magneticfields, and the magnetic fields oppose the change of the main field thusraising electrical resistance and resulting in instant heating of themicrochannel or other flow-permeable structure. In another aspect, ithas been found that corrosion-resistant microtubes of low magnetic 316SS are suited for the application, or a sintered microchannel structureof similar material. While magnetic materials can improve the inductionheating of a metal because of ferromagnetic hysteresis, such magneticmaterials (e.g. carbon steel) are susceptible to corrosion and are notoptimal for generating vapor used to ablate tissue. In certainembodiments, the electromagnetic energy source 440 is adapted forinductive heating of a microchannel structure with a frequency in therange of 50 kHz to 2 Mhz, and more preferably in the range of 400 kHz to500 kHz. While a microchannel structure is described in more detailbelow, it should be appreciated that variations of the devices ormethods can include flow-permeable conductive structures selected fromthe group of woven filaments structures, braided filament structures,knit filaments structures, metal wool structures, porous structures,honeycomb structure and an open cell structures.

In general, a method of treating tissue as described herein can includeutilizing an inductive heater 420 of FIGS. 9-10 to instantly vaporize atreatment media such as deionized water that is injected into the heaterat a flow rate of ranging from 0.001 to 20 ml/min, 0.010 to 10 ml/min,0.050 to 5 ml/min., and to eject the resulting vapor into body structureto ablate tissue. The method further comprises providing an inductiveheater 420 configured for a disposable had-held device (see FIG. 9 )that is capable of generating a minimum water vapor that is at least 70%water vapor, 80% water vapor and 90% water vapor.

FIG. 10 is an enlarged schematic view of inductive heater 420 whichincludes at least one winding of inductive coil 450 wound about aninsulative sleeve 452. The coil 450 is typically wound about a rigidinsulative member, but also can comprise a plurality of rigid coilportions about a flexible insulator or a flexible coil about a flexibleinsulative sleeve. The coil can be in handle portion of a probe or in aworking end of a probe such as a catheter. The inductive coil canextends in length at least 5 mm, 10 mm, 25 mm, 50 mm or 100 m.

In one embodiment shown schematically in FIG. 10 , the inductive heater420 has a flow channel 410 in the center of insulative sleeve 452wherein the flows passes through an inductively heatable microchannelstructure indicated at 455. The microchannel structure 455 comprises anassembly of metal hypotubes 458, for example consisting of thin-wallbiocompatible stainless steel tube tightly packed in bore 460 of theassembly. The coil 450 can thereby inductively heat the metal walls ofthe microchannel structure 455 and the very large surface area ofstructure 455 in contact with the flow can instantly vaporize theflowable media pushed into the flow channel 410. In one embodiment, aceramic insulative sleeve 452 has a length of 1.5″ and outer diameter of0.25″ with a 0.104″ diameter bore 460 therein. A total of thirty-two 316stainless steel tubes 458 with 0.016″ O.D., 0.010″ I.D., and 0.003″ wallare disposed in bore 460. The coil 450 has a length of 1.0″ andcomprises a single winding of 0.026″ diameter tin-coated copper strandwire (optionally with ceramic or Teflon® insulation) and can be wound ina machined helical groove in the insulative sleeve 452. A 200 W RF powersource 440 is used operating at 400 kHz with a pure sine wave. Apressurized sterile water source 120 comprises a computer controlledsyringe that provides fluid flows of deionized water at a rate of 3ml/min which can be instantly vaporized by the inductive heater 420. Atthe vapor exit outlet or outlets 125 in a working end, it has been foundthat various pressures are needed for various tissues and body cavitiesfor optimal ablations, ranging from about 0.1 to 20 psi for ablatingbody cavities or lumens and about 1 psi to 100 psi for interstitialablations.

FIGS. 11A-11D schematically depict a catheter system 600 and method ofuse wherein the catheter is adapted for treating structure in the wallof body lumen, such as treating electrical disorders in various bodytissue. For example such treatments can take place in a patient's heartor in or near nerves carried within or about the wall of a blood vessel.In one example, referring to FIG. 11A, the catheter system 600 can beconfigured for the treatment of chronic hypertension. Hypertension orhigh blood pressure can be a persistent condition in which a patient'ssystemic arterial blood pressure is abnormally high. Hypertension can beclassified as either primary or secondary. About 90%-95% of cases aretermed primary hypertension, which refers to an abnormally high bloodpressure for which no medical cause can be found. The remaining 5% to10% of secondary hypertension can be caused by a variety of otherconditions that affect the kidneys, arteries, heart or endocrine system.Persistent hypertension is a major risk factor for stroke, heart attackand kidney failure. In the progression to later stage persistenthypertension, there is a noted excess activity of the renal nerves. Theprincipal therapies for hypertension comprise oral and intravenous drugsthat act directly or indirectly on the kidney, such as diuretics andangiotensin converting enzyme (ACE) inhibitors. Such drug therapies aremost effective in the early stages of hypertension. In mid- to laterstages of chronic hypertension, the drug treatments are not trulyeffective. Studies have shown that renal denervation can be used tocontrol persistent hypertension which thus may slow the progression tolater- or end-stage disease.

The renal arteries normally extend from the side of the abdominal aorta602 and carry a large portion of total blood flow to the kidneys (FIG.11A). In FIG. 11A, it can be seen that renal artery 605 extends fromaorta 602 to the kidney 608. Up to one third of total cardiac output canpass through the renal arteries for filtration by the kidneys. Thearterial supply of the kidneys is somewhat variable. There may be one ormore renal arteries supplying each kidney. Supernumerary renal arteries(two or more arteries to a single kidney) are the most common anomaly,with such occurrences ranging from 25% to 40%. The mean diameter of arenal artery is in the 5 mm range.

FIGS. 11A-11B depict a process of modifying the electrical signaltransmission characteristics in nerve fibers in an arterial wall whereinan elongated catheter shaft 610 with a working end 615 has beennavigated into the lumen 616 of renal artery 605. A femoral arteryaccess can be used as is known in the art. The catheter working end 615carries an elongated expandable portion that can comprise a balloon 620.The balloon 620 in a collapsed position is configured for insertion andnavigation through lumen 616 and can carry radiopaque markings 622, orthat catheter shaft can have similar markings. The balloon can have alength ranging from about 1 cm to 40 cm with a diameter suited forengaging the wall 624 of the artery. The balloon can be compliant(distensible), non-compliant (non-distensible) or comprise a balloonthat is slightly compliant under high inflation pressures as is known inthe art. One type of balloon can have a wall of Nylon that is complaintat pressures ranging from 2 to 12 bar or more.

Now turning to FIG. 11B, an enlarged sectional view of renal artery 605is shown, wherein the artery wall 624 is comprised of three layers: theinternal intima 626, the muscular media 628 and the external fibrousadventitia 630. FIG. 11B further shows nerves 632 that extend along thelength of the renal artery generally in and about the adventitia and theinterface between the media 628 and adventitia 630 of the vessel wall.FIG. 11B illustrates the catheter working end 615 with the balloon 620in a collapsed position.

FIG. 11C illustrates the working end 615 following actuation of theinflation source 635 and expansion of balloon 620 which is expanded to adiameter that engaged the arterial wall. As can be seen in FIG. 11C, asource of flow media 640 is operatively coupled to a handle end of thecatheter (not shown) and flow channel 644 in the catheter shaft toprovide a high pressure flow of flow media through a jet or microchannelflow outlet 645 in a radial outward portion of the expandable structureor balloon 620. In one embodiment shown in FIGS. 11B-11C, themicrochannel outlet 645 can have a diameter ranging from about 0.0005″to 0.015″ and can be carried in a projecting feature indicated at 648.The projecting feature 648 can comprise an element formed of plastic ormetal and is configured for pressing into tissue of the vessel wall,with a radial or height dimension H of from 0.005″ to 0.100″. FIGS.12A-12B depict the apex or surface 650 of exemplary projecting features648 and 648′ wherein the apex 650 can be flattened or relatively sharpabout the flow outlet 645. FIG. 12C illustrates another embodiment witha plurality of microchannel outlets 645 in the projecting feature 648″.FIG. 12D further depicts that microchannels 645 can be oriented withaxes that converge so that flows 662 can converge with one another at apredetermined depth in tissue to further focus the delivery ofmechanical energy on the targeted tissue site 665 in the vessel wall. Inanother working end embodiment schematically depicted in FIG. 12E, oneor a more hollow micro-needles 680 can be extended from the catheter todeliver the jetted flow media to the targeted tissue. A micro-needlewith an angled tip can be rotated to jet flow media in slightlydifferent orientations to expand the region of damaged tissue. Inanother embodiment, a solid wire microneedle can be penetrated intotissue and the flow media can then follow the path dissected by theneedle penetration. Such a needle can also be rotated and a feature atthe needle tip can be configured to damage or cut nerve tissue. Thesource of flow media 640 can use any type of high pressure pump known inthe art of water jet systems, such as piston pumps, peristaltic pumpsand the like.

FIG. 11C further illustrates the method of using the working end 615 todamage or alter electrical conduction in structures in the vessel wall,wherein the source of flow media 640 and controller 660 are actuated tocause a high pressure flow of flow media indicated at 662 into thevessel wall. In one embodiment, the flow media is saline or sterilewater and the flow 662 can comprise one or more pulses at a pressuresufficient to mechanically cut tissue of the vessel wall and further cutand/or damage nerve fibers 632 in treatment region 665 of the vesselwall to thereby alter electrical signal transmission or transduction.

FIG. 11D illustrates a subsequent step of the method wherein the balloon620 is collapsed and further depicts the treatment region 665 whereinsignal transduction or transmission is altered, diminished orterminated. In the method illustrated in FIGS. 11A-11D, the flow mediacan have an ambient temperature, or can be a cryofluid or a heatedliquid. The pressure require for tissue cutting can range from 100 psito 20,000 psi. In one embodiment, such high pressure pulses can beprovided by a circulating flow that is interrupted by a flow controlvalve as will be described further below in FIGS. 15A-15B. The volume ofthe pulse of flow media can be controlled by this means, as well as thepressure, to provide a flow that delivers mechanical energy to apredetermined depth in tissue before the mechanical energy isdissipated, wherein the predetermined depth of targeted site 665 canrange from 0.1 mm to 2.0. The volume of flow media per pulse of the flow662 can range from 10 to 100 microliters, and a treatment can consist of1 to 20 pulses as depicted in FIGS. 11C and 12A-12D.

In another method, similar to that of FIG. 11C, the flow media cancomprise or include a water vapor component which can undergo a phasechange in or about the targeted site 665 to thereby apply thermal energyto the targeted site as well as mechanical energy to alter theelectrical signaling capability of nerve fibers 632 in the vessel wall.In general, such vapor media can be generated and delivered as describedin previous embodiments above.

Still referring to FIG. 11C, it can be understood that the working end615 can be re-positioned in the lumen 616 in an artery 605 to applyenergy in a plurality of treatment sites. For example, FIGS. 13A-13Cillustrate various patterns of treatment sites that can be discrete andspaced apart or can be overlapping to provide elongated linear, annular,or spiraling regions in which electrical transmission or transduction innerve fibers is altered. Clearly, any variation or combination ofpatterns is within the scope of this disclosure.

FIG. 13A depicts two partly annular treatment regions 665 a and 665 bthat can be created by a plurality of closely spaced jetting outlets 645in the catheter to provide each continuous treatment region (see FIG.14B). FIG. 13B shows a continuous treatment zone 665 c which spiralsabout the vessel. FIG. 13C illustrates four discrete, spaced aparttreatment regions 665 d-665 g that in one method are radially spacedapart at 90°. The scope of the method thus can comprise any annular,partly annular, spiraling, partly spiraling, localized or spaced apartregions or any combination thereof. In one method, a plurality oftreatment regions are spaced apart and non-continuous yet extend from180° to 360° around the vessel within the length of the renal artery.

In the methods described above, as practiced with the working end 615 ofFIGS. 11A-11D, the intima 626 is substantially protected from mechanicalor thermal damage by providing the high pressure jetted flow 662 of flowmedia through the intima to thus provide energy delivery to the interiorportions of the vessel wall. This is advantageous over other thermalablation systems that heat substantial regions of the intima 626 inorder to cause passive heat conduction to the nerve fibers or to causeohmic heating of the nerve fibers. In any embodiment that utilizes aballoon or balloons for engaging the wall of the lumen, the expansionmedia for the balloon can comprise a cooled gas or liquid, either staticor recirculating to cool the vessel wall.

In another embodiment, the flow media can comprise or carrypharmacological agents or ablating fluids, such as BOTOX, alcohol,sclerosing agents, anesthetics and the like, for causing damage to thenerve fibers 632 in the vessel wall.

In FIGS. 11A-11D, the catheter shaft 605 is shown without a guidewirelumen but it should be appreciated that the catheter can have at leastone other lumen for a guidewire or for blood perfusion, all of which arenot shown for convenience only.

Now turning to FIGS. 14A-14B, another embodiment of catheter system 700is shown with a catheter body 705 extending to working end 715. In oneembodiment, the catheter body 705 is configured to spiral about anexpansion balloon 720. In the expanded condition as depicted in FIG.14B, it can be seen that the expanded balloon 720 will press thecatheter body wall into contact with the vessel wall 624. In theembodiment of FIGS. 14A-14B, the high pressure source of flow mediaagain is coupled to lumen 722 in the catheter body 705 that communicateswith a plurality of jets or outlets 725 in the working end 715. Theplurality of outlets 725 can have optionally can have projectingfeatures 648 about each outlet 725 as described in the embodiment ofFIGS. 11A-11D. The outlets 725 can be spaced apart from about 0.020″ to0.2″. Thus, it can be understood that using the working end 715 asdepicted in FIG. 14B will create a plurality of treatment region 665 asdescribed previously in a spiral around the vessel, wherein the spiralpattern can comprise spaced apart treatment regions 665, close adjacenttreatment regions or overlapping treatment regions to thus providenon-continuous or continuous damage to the nerve fibers around thecircumference of the vessel. The method can further consist ofdelivering high pressure jets of flow media to cause mechanical damagein the targeted tissue or thermal energy provided by a vapor media, or acombination of both mechanical energy and thermal effects.

FIGS. 15A-15B schematically depict another aspect of the catheter system700 of FIGS. 14A-14B that is adapted to deliver high pressure pulses ofa flow media, and is based on providing continuous circulating flow of aflow media (liquid or vapor) through the system. Related flow mediacirculation systems are disclosed in Application No. 61/126,647 filed onMay 6, 2008; Application No. 61/126,651 filed on May 6, 2008;Application No. 61/126,612 Filed on May 6, 2008; Application No.61/126,636 filed on May 6, 2008; Application No. 61/130,345 filed on May31, 2008 and Application No. 61/191,459 filed on Sep. 9, 2008 eachincorporated by reference. As can be seen in FIGS. 14B and 15A, the flowmedia source 640 can be actuated to provide a continuous flow of flowmedia through a lumen 722 in the portion of catheter body 705 thatengages the vessel wall (not shown) upon expansion of a balloon or otherexpandable member. FIGS. 15A-15B show only a small portion of catheterbody 705 that is configured with outlets 725. The flow media withininflow channel 722 flows through the working end 715 and then reversesflow outwardly (proximally) in return lumen 732. The return lumen 732 iswithin the catheter shaft 705 and is only shown schematically in FIGS.15A-15B and can be understood to be in shaft 705 in FIGS. 14A-14B. Theplurality of lumens can be parallel in the catheter body or concentric.The flow in the return lumen 732 optionally can be assisted by anegative pressure source 735 fluidly coupled to the return lumen and acollection reservoir (not shown). The negative pressure source also canbe operated by controller 660. A solenoid valve 736 in the return line732 is provided and can be left in the open position as depicted in FIG.15A to thus provide a continuous flow of flow media thru the system. Thecross section of microchannel outlets 725 is substantially small whichthus prevents any significant flow through the outlets when the returnlumen is open. FIG. 15B depicts the actuation of valve 736 to a closedposition for an interval that may range from 0.01 second to 5 seconds ormore which terminates the return flow and causes a pulse of treatmentflows 750 from the outlets 725. The controller 660 can control the flowrate through the system, and then control the closing of valve 736 togenerate the desired depth of mechanical damage caused by a liquid flowmedia. The same flow system can be used for delivering a vapor media tocause thermal effects in tissue, or combination of mechanical andthermal effects.

FIG. 16 is an illustration of another embodiment of catheter system 755which includes a catheter body 756 that diverges into a plurality ofbody portions 758 a and 758 b that can spiral about expansion balloon760 or the body portions can be longitudinal relative to the balloon760. A balloon inflation lumen is provided in catheter body portion 764.In this embodiment, the flow media outlets 765 are again disposed aboutthe radially-outward surfaces of the catheter body portions 758 a and758 b and can function as described in the embodiment of FIGS. 14A-14B.Again, the method of use consists of delivering high pressure jets offlow media to cause mechanical damage in the targeted tissue or thermalenergy provided by a heated liquid or vapor media, or a combination ofboth mechanical energy and thermal effects. It should be appreciatedthat the catheter body portions 758 a and 758 b also could be moved tothe expanded positions by a central pull-wire that would articulate thecatheter body portions outwardly. Further, in any embodiment, thecatheter body portion can range from two to six or more.

FIG. 17 illustrates another embodiment of catheter system 800 whichincludes a catheter body 802 that extends to an articulating working end810 that is configured to engage the vessel wall without a balloon as inseveral previous embodiments. The working end 810 can be articulated byan interior pull wire 812. In this embodiment, the flow media outlets815 again disposed in the radially-outward surface of the catheterworking end when in the expanded position. As described previously, themethod of use consists of delivering high pressure jets of flow media825 to cause mechanical damage in the targeted tissue or thermal effectsfrom vapor media, or a combination of both mechanical energy and thermaleffects. It should be appreciated that the embodiment of FIG. 17 caninclude articulating the working end 810 to provide a substantiallyannular treatment region (or pattern) or a spiral treatment region ofany suitable geometry.

FIG. 18 illustrates another embodiment of catheter system 850, and moreparticularly a portion of catheter working end 855 that includes firstand second media inflow channels 860A and 860B that are coupled toindependent pressurized sources of flow media. A first source 865Acomprises a water jet liquid media source, for example that isconfigured to jet saline or another liquid at high pressure to cuttissue and thereby cause mechanical damage to tissue. The second flowsource 865B comprises a source of water vapor that is adapted forcausing thermal effects in tissue. A first return flow channel 866A isdistally coupled to the first inflow channel 860A to allow arecirculating flow as described previously with valve 888 a configuredto provide high pressure liquid media jets 890 being ejected from aplurality of outlets 892. A second return flow channel 886B is distallycoupled to second inflow channel 860B to again allow a recirculatingflow which is controlled by valve 888 b in the manner described above.FIG. 18 shows high pressure vapor jets 895 being propagated from outlets896 to cause thermal effects in the targeted tissue. In one embodiment,the liquid cutting jets 890 and vapor jets 895 can be pulsedalternatively or pulsed contemporaneously to delivery vapor the targetedregion of the adventitia to damage nerve fibers therein. In one aspectof the method, the liquid cutting jet provides a dissected path tothereby permit vapor to propagate more effectively to the region of thenerve fibers and to allow greater vapor condensation and energy deliveryin the targeted region. The controller 660 and negative pressure source735 can operate as described previously. It should be appreciated thatthe first and second media inflow channels 860A and 860B can intersectproximal to a single outlet to thus provide a single outlet and pathwayfor intermittent pulses of liquid and vapor jets. In this embodiment, asingle outflow channel could be optionally be used along with a valvesystem to control the first and second media flows in the catheter. Suchsingle or multiple inflow channels that intersect also can be used tomix flowable media to control the temperature of the ejected flow with acooled gas or liquid, to add substances such as pharmacological agentsor abrasives to the flow or the like.

In general, another variation of a method for modifying structure in atargeted wall of a lumen comprises engaging the targeted wall with atleast one engagement surface of an instrument working end andpropagating a flowable media at a substantial velocity from at least oneoutlet in the engagement surface into the targeted tissue, wherein theflowable media modifies the structure in the targeted wall to modifyelectrical signal transmission therein. The method includes flowablemedia causing at least one of mechanical and thermal effects to modifythe nerve fibers in the targeted wall. The method includes usingflowable media that comprises water vapor and/or water droplets. In onemethod, the targeted tissue is in the renal arteries.

In another embodiment and method, the vapor can be generated from atleast one of water, saline and alcohol. Further, the method can includeintroducing at least one pharmacologically active agent with the vapor.The pharmacologically active agent can be at least on one of ananesthetic, an antibiotic, a toxin and a sclerosing agent. Further, themethod can included introducing an imaging enhancement media with thevapor.

The method of generating the flow of vapor can be by at least one ofresistive heating means, inductive heating means, radiofrequency (RF)energy means, microwave energy means, photonic energy means, magneticinduction energy means, compression and decompression means togetherwith heating means, and ultrasonic energy means.

FIGS. 19-21 illustrate another embodiment of the invention that can beused for tumor ablation as well as, other soft tissue treatments, orother applications involving the application of energy as describedherein. In one embodiment, the system comprises a vapor delivery tool900 with a handle 902 that is coupled to an elongate vapor deliverymember 910 with a working end 912 configured as a sharp-tip needle. Theworking end 912 has a plurality of vapor outlets 915 therein.

The handle 902 carries an inductive heating system for applying energyto a flow of liquid media in a flow channel therein, which is shown inexploded view in FIG. 21 . As can be seen in FIG. 21 , a liquid mediasource 920 and pump 922 provide a flow of liquid media to an interiorchannel 924 in an inductively heatable metal structure that in onevariation comprises a stainless steel tubing formed into a helicaltubing form 925. In one variation, the helical tubing 925 has aninterior lumen or channel diameter of between 0.02″ and 0.06″ andchannel length of between 50 cm and 200 cm. The outside diameter of thehelical tubing assembly can be from 5 mm to 20 mm. In one variation, thehelical tubing 925 can be formed so that each winding contacts anadjacent winding or the windings of the tubing can be dipped in a formof solder or similar inductively heatable material so that the entireassembly can be inductively heated efficiently. It should be appreciatedthat multiple sets of helical tubing 925 can be provided in a concentricassembly with one flow channel extending therethrough for providing anincreased length flow channel. As with additional variations describedherein, the dimensions of the device can vary as needed for theparticular variation or application.

In a typical flow-based vapor delivery system described herein, oneexample of a pump 922 capable of being used with the system is a type ofsyringe pump known in the art that uses a stepper motor operativelycoupled to controller 960 that allows for very precise control of flowrates of liquid media into the system.

It also has been found that a flow-based vapor delivery system asdescribed herein is well suited for high velocity projection of vapormedia from a probe working end to apply mechanical energy to dissecttissue, as disclosed in co-pending U.S. patent application Ser. No.12/941,778 which is incorporated herein by reference.

In another embodiment, at least one type of electrical sensor can beprovided in the fluid flow channel upstream and/or downstream of theinductively heatable helical tubing 925 with such a sensor configured tosend signals to the controller 960. An upstream sensor can be animpedance or capacitance sensor to detect liquid media flows. Such asensor can signal the controller of a normal flow and can detect a faultin the system, for example a failure of the pump 922, or a leak or kinkin a liquid supply tubing that prevents a liquid flow through thesystem. A signal from such an upstream sensor can alert the user, orautomatically shut down the system. A downstream sensor consisting of animpedance or capacitance sensor can signal the controller of a vaporflow rate or vapor quality based on an algorithm and look-up table ofknown impedance/capacitance values for flow rates and vapor quality.Again, such sensors can alert the user and/or automatically shut downthe system if the system is not operating at selected or desiredoperational parameters.

In another embodiment described above that uses real-time imaging of avapor ablation procedure, (e.g., ultrasound, MRI, etc.), the controllercan be configured with additional algorithms that automatically altervapor delivery parameters in response to imaging data of the treatmentsite. The modulation of energy delivery parameters can include at leastone of vapor flow rate, vapor pressure, vapor delivery interval, vaporquality and orientation or programmed movement of the probe's vapordelivery outlets relative to the targeted site.

In another embodiment, the vapor delivery channel downstream from thevapor generator can be pre-heated to prevent condensation of vapor wheninitiating use of the “cold” system that has a vapor delivery channel atroom temperature. In one variation, the vapor delivery channel includesa resistive heating element adapted to pre-heat the channel wall or aplastic or other PTC (positive temperature coefficient) material thatallows heating of the channel wall. In any of these variations, atemperature sensing mechanism can communicate with the controller andinterlock algorithm to signal user and to prevent vapor delivery beforethe channel wall reaches a selected temperature.

Referring to FIGS. 19 and 21 , an electrical source or RF source 940 isoperatively connected to a copper wire coil 950 that surrounds thehelical tubing 925. The coil 950 does not physically or electricallycontact the inner stainless steel helical tubing 925 and in oneembodiment an insulator sleeve 955 is provided which can be any polymeror other dielectric material. In one variation, the copper coil 950 cancomprise Litz wire which consists of multiple small insulated wires thatcan increase the power-carrying capacity of the coil. The RF source 940can be configured for delivery of between 1 W and 3000 W. As can be seenin FIGS. 19 and 21 , a controller 960 is provided for integrated controlof both the pump 922 and the RF source 940. Electrical cables from theRF source 940 and flow tubing from the liquid media source 920 can beprovided in a single conduit 962 which can be integrated with thenon-disposable handle 902 or can be coupled to the handle 902 with asingle detachable connector or a plurality of connectors.

It can be understood that all design parameters related to the RF source940 and liquid flows in the system are inter-related, and in general,the system design can be based on the ultimate “cal/sec” rate ofapplying energy to tissue that is optimal for a particular procedure. Ingeneral, the inter-related design parameters include (i) ml/min ofliquid media flow within the inductively heatable structure whichfurther is dependent on flow channel diameter, flow channel length, andflow pressure; (ii) the Watts delivered by the RF source 940 whichfurther relates to coil design (number of windings, types of wires incoil) and calculation of losses in the system to thereby apply selectedWatts to the coil 950; and ultimately the vapor quality (i.e., thepercent of the flow exiting a system vapor outlet that is phase changedto pure vapor as opposed to non-phase changed which may be liquiddroplets). In one variation described below, the system provides a vapormedia flow that is greater than 90% pure vapor and further provides anultimate conversion efficiency of electrical energy to vapor energy ofat least 60%.

In one variation, the system includes an RF source 940 that delivers 150W, uses water as a liquid media source with a pump 922 providing a flowrate of about 2.8 ml/min into a helical channel having a diameter of0.05″ and a length 90 cm with the helical tubing assembly having adiameter of 10 mm. The coil 950 surrounding the helical tubing deliversabout 110 W to the helical tubing which results in 92% pure vapor atabout 75 ml/min of vapor.

Referring to FIG. 19 , it can be seen that the handle 902 which carriesthe helical tubing 925 and coil 950 is re-useable and detachable fromelongate member 910 with a screw fitting 964. The handle 902 and moreparticularly the fluid channel 924 therein can be sterilized by runningvapor through the system for a period of 1 to 10 minutes. The elongatemember 910 in the embodiment shown in FIG. 19 comprises a vapor deliveryneedle which is disposable. The working end 912 of the elongated member910 can comprise an exposed portion of a 16-30 gauge stainless steelneedle shaft 965 having any suitable exposed length and any suitablenumber of vapor outlets 915 as described previously. As be seen in FIG.19-21 , the elongated member has an increased diameter section 970 thatcomprises an insulated section. In one variation shown in FIG. 22 , aninsulative space 972 can be air or a vacuum in a concentric space aroundthe needle shaft 965. The outer sleeve 975 can be thin-wall stainlesssteel. In another embodiment, the insulative space 972 can be an aerogelor other insulative material and the outer sleeve 975 can be a metal orpolymeric material. The dimensions of the insulative space can bedesigned to prevent the outer sleeve 975 from reaching a predeterminedmaximum temperature based on a particular vapor delivery interval duringwhich vapor is flowing through the needle shaft 965.

FIG. 23 illustrates another variation 900′ which is similar to theembodiment of FIGS. 19-21 except that the handle 902′ carries only thecoil 950 which functions as described above. In the embodiment of FIG.23 , the elongate member 910′ and helical tubing 925′ comprise anassembly 980 which is detachable from handle 902′. The assembly 980 canslide into passageway 982 in the handle 902′ and thus mate and cooperatewith coil 950 for vaporizing a flow of liquid media therethrough. Theassembly 980 has a proximal quick-connect fitting 984 that extendsproximally from passageway 982 when mated with handle 902′ to which acooperating fitting (not shown) can be coupled to provide the liquidflow from the liquid media source 920. In this embodiment, an electricalcable 986 from the RF source 940 is coupled directly to handle 902′.

A method corresponding to the invention utilizing the system of FIGS.19-21 or as otherwise described herein, for applying energy to a bodystructure includes controlling the flow of liquid media into theinductively heatable helical tubing structure 925 by utilizing thecontroller 960 to operate the pump 922, wherein the controlled flow ofliquid media is then converted to vapor media having a predeterminedflow rate to thereby provide a predetermined application of energy totissue which be quantifiable, e.g., in cal/sec. Of particular interest,the use of the controlled liquid media flow allows delivery of a knownamount of energy to tissue, or rate of energy delivery, which is notaffected by the resistance of tissue to vapor propagation. In anotherform of vapor delivery system which delivers vapor from a boiler asdescribed in co-pending U.S. patent application Ser. No. 12/167,155filed Jul. 2, 2008, the pressure under which vapor is delivered intotissue is a function of boiler design and can be adversely affected byback-pressure or resistance within the targeted tissue, particularly indense tissue, non-uniform tissue or fibrous tissue. In the use of such a“pressure-based” flow system, it is difficult to accurately determinethe actual “rate” of energy delivery in dense or non-uniform tissue andtherefore and it is difficult to set the appropriate vapor delivery timeinterval in seconds or minutes to ablate a particular targeted tissuevolume. Thus, in general, a method corresponding to the inventionconsists of positioning a working end of a vapor delivery system at atargeted site in a body, providing a liquid media flow at a selectedflow rate in the system and converting the liquid media to vapor mediathereby providing a corresponding vapor flow rate and delivering thevapor media to the targeted site for selected time interval to therebyprovide corresponding energy application ranging between 1 cal/sec to500 cal/sec. In this method, the selected fluid flow rate can becontrolled by controller 960 and pump 922 to provide liquid flow between0.01 ml/min to 50 ml/min. In one variation, the liquid media is wateralthough other fluids such as alcohol, etc. can be used. In this method,the corresponding vapor flow rate can be between 1 ml/min and 1500ml/min of water vapor. The RF source 940 can be controlled by controller960 to apply between 1 W and 3000 W for converting the liquid media tovapor media. The method includes allowing the physician to select atreatment time interval of between 1 sec and 5 minutes on thecontroller's user interface.

In another method of the invention, the controller 960 is configured tobe programmable to allow the physician to select a vapor treatment thatapplies energy at a constant rate over a selected time interval. Inanother variation, the controller 960 is configured to allow thephysician to select a vapor treatment that applies energy at a firstconstant rate over at least a first time interval, and thenautomatically at second constant rate over at least a second timeinterval. In yet another variation, the controller 960 can be configuredto allow the physician to select a vapor treatment that modulates theapplied energy over a selected time interval. In one embodiment, thecontroller has a user interface that allows selection of at least one of(i) the liquid media flow rate, (ii) the energy application rate; (iii)the vapor flow rate; and (iv) the vapor delivery time interval orintervals.

In another method of corresponding to the invention, the vapor deliverysystem and controller 960 are provided with an “idle” feature whichidles the liquid and vapor flows at a very low level which is useful topre-heat the flow channel and/or maintain the flow channel at a hightemperature to thus allow for “instant-on” energy delivery without anyappreciable condensation in the flow channel upon initiation of typicaltherapeutic liquid and vapor flows. In general, the physician can usethe vapor idle feature with the system of FIGS. 19-21 which can includeintroducing a first flow of liquid media at a first liquid flow rate andconverting the liquid media to vapor media, wherein the first vapor flowrate is configured for pre-heating and/or maintaining heat in the flowchannel, and thereafter introducing a second flow of liquid media atsecond flow parameters and converting the liquid media to vapor mediawherein second vapor flow rate is configured for exiting at least onevapor outlet to thereby apply energy to the body structure. Thephysician typically can use the idle feature before positioning theworking end of the system in, or proximate to, the targeted site in apatient's body. The vapor idle feature has the further advantage ofpreventing gas and/or body fluids from migrating into the least onevapor outlet. The idle feature typically utilizes a liquid media flowrate of less than 1.0 ml/min. The system generally has a therapeuticliquid media flow rate that is greater than 1.0 ml/min.

In one variation of the system of FIGS. 19-21 , the liquid media flowrate is selected by physician inputs on the user interface, and thecontroller 960 and RF source 940 deliver energy within a predeterminedrange suited for phase changing the liquid media flow to a vapor flow.As can be seen in FIG. 19 , a temperature sensor 988 is coupled to thehelical tubing 925 which sends temperature signals to the controller960. The controller then includes algorithms for modulating RF power tomaintain the temperature of the helical tubing at a predeterminedtemperature, for example 120° C., although the targeted temperaturecould be any suitable temperature for the liquid media being supplied(e.g., 90° C. to 150° C.). The helical tubing 925 and flow path 924within the system also can be configured with a pressure sensor 990 andan optional flow meter 992 independent of the pump 922, allcommunicating with the controller 960. In one embodiment, the controllerhas an algorithm that disables energy delivery from the RF source 940 ifthe temperature signals from the temperature sensor 988 are too high orthe average temperature is too high over an interval or 1-20 seconds. Inanother variation, the controller 960 includes an algorithm thatdisables energy delivery from the RF source 940 if pressure sensed bythe pressure sensor 990 is too high or averages pressure is too highover an interval or 1-20 seconds. In another variation, the controllerincludes an algorithm that disables energy delivery from the RF source940 if the sensed flow rate from flow meter 992 does not correlate withthe pre-selected flow rate that is supposed to be provided by the pump922. The system also can include at least one pressure relief valve (notshown) in communication with the flow channel 924 to prevent unwantedpressure build-up within the system.

In general, the vapor treatment system comprises a handle 902 with anelongated member 910 coupled to the handle, an electrical sourceoperatively coupled to a coil 950 within the handle 902, an inductivelyheatable structure 925 positioned proximate to the coil, a pump 922 andliquid media source 920 in communication with a flow channel 924 in thestructure, the flow channel having an least one outlet 915 in a distalend of the elongated member, a controller operatively coupled to theelectrical source and pump and at least one of a flow sensor, pressuresensor and temperature sensor for sending signals of operatingparameters to the controller wherein the controller is configured tooperate the electrical source and pump at selected parameters toinductively heat the structure to thereby convert a flow of the liquidmedia to a flow of vapor media in the flow channel which exits the atleast one outlet to apply energy to body structure. The systemcontroller includes a user interface configured with user-selectablepre-selects for at least one of (i) liquid media flow rate, (ii) liquidmedia flow interval, (iii) modulation of the liquid media flow ratewithin a time interval, (iv) energy application rate corresponding toenergy released in a phase change of vapor to liquid, (v) pulsed flowsof the liquid media and (vi) total applied energy. The system controllerincludes an algorithm to modulate electrical energy applied to the coilto maintain the temperature of the inductively heatable structure withinany selected temperature range is between 90° C. and 150° C. In anotherembodiment, the system the controller includes an algorithm to modulatethe liquid media flow rate to maintain the temperature of theinductively heatable structure within a selected range. In anotherembodiment, the system controller includes an algorithm and look-uptable configured for selection of operating parameters of the electricalsource corresponding to each user-selected liquid media flow rate.

In another method of the invention, it has been found that ablatingcertain soft tissue volumes such as tumors can be accomplished optimallyby providing initial interval with vapor delivery parameters including apulsed vapor flow followed by a second time interval with secondparameters in which the vapor flow optionally is not pulsed. It has beenfound that first pulsed vapor flows and optional lower applied energyrates will shrink cell membranes and open extracellular spaces tothereafter allow higher vapor flows and applied energy rates whichcauses vapor to propagate extracellularly and to thereby cause completecell death in a targeted tissue volume.

In general, a method for delivering energy to body tissue comprisesintroducing a working end of a vapor delivery probe into a targeted sitein tissue, providing a flow of a condensable vapor under firstoperational parameters from the working end to modify the targeted siteto permit enhanced extracellular vapor propagation therein and thenproviding a flow of the condensable vapor under second different flowparameters from the working end to cause cell death in the targetedsite. The first operational parameters can includes a first flow ratethat is higher or lower than a second flow rate of the second flowparameters. In one variation, the first operational parameters include apulsed flow. In another variation, the second operational parametersinclude a non-pulsed flow.

In one embodiment, the vapor delivery system includes a flow channelextending to at least one outlet in a working end, a liquid media sourceand pump system configured to provide a flow of the liquid media intothe flow channel, a heat source for converting the flow of the liquidmedia into a flow of vapor media in the flow channel and a controlleradapted to control operating parameters of the liquid media source andheat source wherein the controller includes a user interface configuredwith user-selectable pre-selects for at least one of (i) liquid mediaflow rate, (ii) liquid media flow interval, (iii) modulation of theliquid media flow rate within a time interval, (iv) energy applicationrate corresponding to energy released in a phase change of vapor toliquid, (v) pulsed flows of the liquid media and (vi) total appliedenergy corresponding to energy released in a phase change of vapor toliquid. The controller can includes algorithms and a look-up tableconfigured for selection of an operating parameters of the electricalsource corresponding to each user-selected liquid media flow rate. Thecontroller can include algorithms for modulating the liquid media flowrate in response to sensed temperature of an inductively heatablestructure or the controller can include algorithms for modulatingoperating parameters of the heat source in response to a sensedtemperature of the inductively heatable structure.

It has been found that the flow-based vapor delivery system as describedabove is optimal for many tissue ablation procedures, wherein the methodfor treating a site in a body structure, comprising positioning aworking end of a vapor delivery probe at or proximate to a targeted sitein a body and utilizing a pump system to provide a flow of liquid mediaat a predetermined fluid flow rate into the probe and converting theliquid media to vapor media thereby providing a corresponding vapor flowrate to the site, wherein the pump system is configured to deliver theliquid and vapor media at a substantially constant rate not affected byresistance to the flow of vapor media to the site. In one treatment, thetargeted site is benign or malignant tumorous tissue. In anothertreatment, the targeted site is a uterine fibroid. In another treatment,the targeted site is lung tissue. In another treatment, the targetedsite is a lung tumor or nodule. In another treatment, the targeted siteis the inner lining of an esophagus. In another treatment, the targetedsite is within a wall of a renal artery or the wall of a carotid artery.In another treatment, the targeted site is a baroreceptor or carotidbody. In another treatment, the targeted site is nerve tissue. In oneprocedure, nerves can be ablated to treat migraine headaches. In anothertreatment, the targeted site is selected from the group including skin,adipose tissue, bone, disc, disc nucleus, ligaments, cartilage, synovialtissue, myelomas, cervical tissue, endometrium, digestive tract tissue,stomach walls, intestinal walls, hemorrhoids, soft palate, tonguetissue, an ulcer, wart, lymph node, breast duct, sinus tissue, arterialand venous malformations, vasculature, brain tissue, nerve roots in atooth, heart tissue and eye tissue.

In another method of the invention, an imaging system can be used inconjunction with vapor delivery to visualize the vapor in real timeduring a procedure to ensure that the vapor is being delivered to thetargeted site and/or to determine that an adequate vapor volume has beendelivered to the site is soft tissue or within a body cavity or lumen.In one variation, ultrasound can be used for visualization because vaporis hyperechoic so what one sees on ultrasound can be exactly thetreatment area. In another variation, magnetic resonance imaging can beused to show the temperature profile in tissue in almost real-time. Inanother variation, a CT scan can be used and vapor can be imaged if acontrast agent (e.g., Iodine) is added to the liquid media source.Further, data from any of these imaging systems can be sent to acomputer software program that can convert the data into 3D images on ascreen which can then be used together with a tracking device on the tipof the vapor delivery probe to guide the tip to the target site intissue.

In another embodiment, the user interface in the controller 960 can beadapted to generate an image representation of a potential treatmentsite in a subject on a screen. The physician then outlines on the screena targeted treatment site in 2D or 3D. Thereafter, the controller 960can use the “outlined” treatment site on the screen to determine theoptimal treatment operating parameters to ablate the site.

FIG. 24 illustrates another apparatus and method of the invention fortreating a blood pressure disorder by using thermal energy to modifyfunction of a baroreceptor in a human or mammalian body. Baroreceptorsconsist of a form of mechanoreceptor that detects pressure of a bloodflow in a vessel lumen which can signal the central nervous system toincrease or decrease total peripheral resistance to blood flow andcardiac output. Baroreceptors function as a component of a negativefeedback system called the baroreflex to alter mean arterial bloodpressure. Arterial baroreceptors are stimulated by stretching ordistortion of the arterial walls when blood pressure changes. Thebaroreceptors can identify the changes in both the average bloodpressure or the rate of change in pressure with each arterial pulse, andcan signal the nervous system in response to such stretching. FIG. 24illustrates a vapor delivery catheter 994 having a working end 995navigated within carotid artery 996 to a location proximate abaroreceptor 997. A vapor delivery needle tip, similar to that of FIG.11E, can be introduced into the baroreceptor tissue to deliver vapor toablate or modify function of the baroreceptor. Any of the working endembodiments with positioning balloons of FIGS. 11B-18 can be used totreat a baroreceptor.

FIG. 25 illustrates another method and apparatus of the invention fortreating a cervical neoplasia. Cervical intraepithelial neoplasia (CIN)is routinely treated with a procedure called conization. Such conizationof the cervix 998 is defined as excision of a cone-shaped or cylindricalwedge from the cervix that includes the transformation zone andpotentially portions of the endocervical canal 999. In FIG. 25 , thesystem and probe 1000 have a working end 1005 that includes a vapormedia inflow channel extending to a concavity of the working end thatengages tissue and contains the vapor media. In the embodiment of FIG.25 , the probe introducer or shaft 1010 extends along axis 1015 from ahandle (not shown) to a bell-shaped structure 1016 with a perimeter 1020that contacts tissue about the cervix 1022. The diameter of theperimeter can range from about 1 cm to 4 cm and in one embodiment, thebell-shaped structure 1016 is a resilient silicone. The structure 1016provides a concavity 1025 which contains vapor media. The thickness ofthe structure 1016 is sufficient to permit the physician to press thestructure into tissue and to prevent vapor escape around the perimeter1020.

FIG. 25 further illustrates an elongate vapor delivery sleeve 1030 thatis axially slidable in bore 1032 in the bell-shaped structure 1016. Thesleeve 1030 carries an expandable member such as occlusion balloon 1040that is configured for expansion in the cervical canal 1042 to seal thecanal at a selected location therein. Thus, the axial dimension betweenthe bell-shaped structure 1016 and occlusion balloon 1040 is adjustableto allow the physician to position the balloon at any shallow or deeperdepth in the endocervical canal. The balloon 1040 is inflated from aninflation source 1045 that can comprise a syringe or other mechanism forproviding a pressurized liquid or gas to inflate the balloon.

In a method of use, still referring to FIG. 25 , vapor is introducedfrom vapor source 1050 and controlled by controller 1055 through a lumenin vapor delivery sleeve 1030 to exit outlets 1060 distal to bell-shapedstructure 1016. The vapor then condenses and releases energy to contactand ablate tissue intermediate the bell-shaped structure 1016 and theocclusion balloon 1040. The vapor can be provided in a treatmentinterval ranging from 10 seconds to about 4 minutes to ablate to anydesired depth, which can be from 0.5 mm to 1 cm or more. In anotherembodiment, the perimeter of the bell-shaped structure 1016 and/or theballoon 1040 can be infused with a cooling fluid to cool adjacenttissue. The bell-shaped structure 1016 and optionally the balloon 1040can carry thermocouples that are operationally connected to thecontroller to modulate or terminate energy delivery.

In general, a method of the invention of treating a cervical neoplasiacomprised generating a flow of vapor, positioning a vapor containingstructure about the external cervical os, introducing the flow of vaporinto contact with targeted cervical tissue, delivering thermal energy tothe targeted tissue via a vapor-to-liquid phase transition of the vapor,and modifying the targeted tissue. The method includes the delivery ofwater vapor, and optionally can deliver a pharmacological agent. Thecervical tissue can be ablated to a depth of at least 0.5 mm, at least 1mm, at least 2 mm, at least 3 mm, at least 4 mm or at least 5 mm. Thecervical tissue can be ablated radially outward from the external os adistance of at least 1 mm, at least 5 mm, or at least 10 mm. The methodincludes positioning the containment structure by manually pressing aperimeter of the containment structure against the tissue outward of theexternal cervical os.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

What is claimed is:
 1. A medical system for applying energy to tissue,comprising: a handle; an elongate member coupled to the handle, theelongate member comprising a proximal end and a distal end; a coil inthe handle having a flow channel extending helically therein, the flowchannel being coupled to a liquid media source, the coil being coupledto a flow channel in the elongate member; a pump configured to cause theflow of liquid media from the liquid media source to the flow channel;an electrical source coupled to the coil such that delivery of energy tothe coil converts the flow of liquid media to a flow of vapor media viaresistive heating of the flow channel; a controller operatively coupledto the electrical source and pump; a temperature sensor within thehandle and coupled to the coil, wherein the temperature sensorcommunicates with the controller to adjust the temperature of the flowchannel; and a pressure sensor within the handle, wherein the pressuresensor communicates with the controller to adjust the delivery of energyto the coil.
 2. The medical system of claim 1, wherein the elongatemember comprises a flexible catheter.
 3. The medical system of claim 1,wherein the distal end of the elongate member comprises a needle.
 4. Themedical system of claim 1, wherein the controller is configured tocontrol the flow from the pump.
 5. The medical system of claim 4,wherein the controller is responsive to signals from the temperaturesensor to control the flow from the pump.
 6. The medical system of claim1, wherein the flow channel of the elongate member is coupled to anaspiration source.
 7. The medical system of claim 1, wherein the flowchannel of the elongate member is coupled to a second liquid mediasource.
 8. The medical system of claim 1, wherein the handle and theelongate member are detachable from each other.
 9. The medical system ofclaim 1, wherein the handle and the coil are detachable from each other.10. The medical system of claim 1, wherein the distal end of theelongate member carries at least one balloon.
 11. The medical system ofclaim 1, wherein the distal end of the elongate member has anextendable-retractable needle.
 12. The medical system of claim 1,wherein the flow channel in the elongate member is surrounded by aninsulative space comprising air or a partial vacuum.
 13. The medicalsystem of claim 1, wherein the flow of vapor media in the flow channelhas a vapor flow rate, wherein the vapor flow rate is configured for atleast one of pre-heating and maintaining heat in the flow channel toconvert the flow of liquid media to a flow of vapor media.
 14. Themedical system of claim 1, wherein the flow of the liquid has a firstflow rate, wherein the first flow rate is less than 1.0 ml/min.
 15. Themedical system of claim 1, wherein the energy applied for converting theliquid media to vapor media is between 1 W and 3000 W.